This invention relates to hydrant constructions and is particularly directed to a nonfreezing, sanitary hydrant.
Many hydrants of different types are in use in outdoor areas, such as farms, parks, roadside rests, recreational areas, and the like. One requisite of many of these hydrants is that they be of a nonfreezing type so that they may be freely operated in all types of weather, including subfreezing temperatures. In order to provide such a nonfreezing hydrant, all water in the hydrant structure above the frost line must be drained subsequent to each use of the hydrant. Originally this drainage was accomplished by providing a suitable opening at the lower end of the hydrant which led to a porous filling in the ground surrounding the hydrant. While such a hydrant construction does avoid the freezing problem, it introduces another, equally serious difficulty. Specifically, under certain circumstances, a siphonage action can be created whereby ground water is siphoned from the surrounding ground area back into the water line contaminating the water supply.
In the past there have been proposals to solve such difficulties by providing hydrants which are both frostproof and sanitary, i.e., hydrants which contain their own reservoir in which water drained from the upper part of the hydrant is stored subsequent to each use. Typical patents showing constructions of this type are Stephenson U.S. Pat. No. 49,801; Normal U.S. Pat. No. 2,017,767; Hobbs et al U.S. Pat. No. 2,675,825; Boosey U.S. Pat. No. 2,598,968; and Schmid et al U.S. Pat. No. 2,605,781.
Those sanitary hydrant constructions which have proven sufficiently practical to be commercialized have still been subject to serious disadvantages. In the first place, such constructions have been quite expensive. Moreover, they have been relatively bulky and difficult to service.